Патент USA US2110977код для вставки
1:" 2,110,977 G. A. KOHOUT FUEL FEEDING CONTROL DEVICE FOR FURNACES Filed Sept. 25, 1933 7 Sheet's-Sheet 1 March 15, 1938. G, A, KOHQU‘T 2,110,977 7 FUEL FEEDING CONTROL DEVICE FOR FURNACES Filed Sept. 25, 1933 ‘ 7 Sheets-Sheet 2 I geocgc’ Q. ?Z/zaag “a, W ‘% March 15, 1938. 2,110,977 G, A. KOHOUT FUEL FEEDING CONTROL DEVICE FOR FURNACES Filed Sept. 25, 1933 7 Sheets-Sheet 3 [hue/dial“ ’ Gearye QUZIZ/ZOCLZ‘ March 15, 1938. 2,110,977 G. A. KOHOUT FUEL FEEDING CONTROL DEVICE FOR FURNACES Filed Sept. 25, 1953 7 Sheets~Sheet 4 M6 6607 .j WM 01% March 15, 1938. \ G A KQHQUT 2,110,977 FUEL FEEDING CONTROL‘DEVICE FOR FURNACES Filed Sept. 25, 1933 '7 Sheets-Sheet 5 $596 T9 f. C__________ \ v ?zz/621507“ 6607" (‘3 Q. flZ/zoui’ 31/‘ M4464 March 15, 1938. a G‘ A, KOHQUT I 2,110,977 FUEL FEEDING CONTROL DEVICE FOR FURNACES Filed Sept. 25,v 1953 - 7 Sheets-Sheet 6 L11 March 15, 1938. 2,110,977 a. A. KOHOUT FUEL FEEDING CONTROL DEVICE FOR FURNACES Filed Sept. 25, 1933 S»? _a.__i_____ i AR@$1 7 Sheets-Sheet 7 Patented Mar. 15, 1938 2,110,9l'l UNITED STAT PATENT OFFEQE 2,110,977 FUEL FEEDING CONTROL DEVICE FOR FURNACES George A. Kohout, Chicago, Ill. Application September 25, 1933, Serial No. 690,797 7 Claims. (Cl. 126-169) My invention relates to furnaces and more par ticularly to a control system for providing ?exible Fig. 10 is a front View of a portion of the drive shaft and the mechanism for conecting it to the supervisory control of automatically operated furnaces, grate actuating mechanism; In furnaces which the feeding of fuel is automatically stopped or started in response to changes in boiler pressure, furnace temperature, lapse of time or other control factors, the prob lems of controlling the rate of feeding while the 10 feeding mechanism is in operation and the time sequence of operating the different units of a multiple unit feeding mechanism present certain dif?culties. It is a purpose of this invention to provide a 15 control system which may be used in conjunction with automatic furnace controls to adequately regulate the rate of fuel feeding during the pe riod of operation of the fuel feeding mechanism. It is also a purpose of my invention to provide in a multiple unit fuel feeding system a novel con trol means for maintaining a de?nite time se quence of operation of said units which also makes possible independent operation of any unit at any time. My invention contemplates also the provision of a novel control mechanism for controlling the length of time interval separating the a-ctuations of the fuel feeding units. Other and more speci?c objects of the inven tion will appear as the description proceeds in connection with the accompanying drawings. It is to be understood, however, that the drawings and description are illustrative only and are not to be taken as limiting the invention except in so far as it is limited by the claims. In the drawings Fig. l is a side view partly in section illustrat ing a furnace of the stoker grate type to which my invention is applied; Fig. 2 is a sectional view substantially on the line ‘2—2 of Fig. 1 showing the multiple fuel feed ing units or stoker grates; Fig. 3 is a vertical section through a part of the control mechanism employed; Fig. 4 is a section on the line 4—4 of Fig. 3; 5 is a section on the line 5-—5 of Fig. 3; Fig. 6 is a section on the line 5-5 of Fig. 3; Fig. '7 a top plan View of a portion of the top of the control box shown in Fig, 3 illustrating the 50 control lever for setting the mechanism in the box of Fig. 3; Fig. 8 is a front view with the cover removed of one of the solenoid units for connecting the drive shaft to the various fuel feeding units; Fig. 9 is a section on the line 9—9 of Fig. 8; Fig. 11 is a section on the line li—|l of Fig. 10; and Fig. 12 is a diagrammatic View illustrating the electrical connections to the various control ele ments for operating the fuel feeding units. In illustrating my invention, I have applied it to a furnace where the fuel is fed down over the grates from the inlet by means of a series of stoker grate units in which the grate bars are rocked upon their pivots to move the fuel away from the entrance. In fuel feeding devices of this character, it is common to employ the con~ trol mechanism for stopping and starting the fuel feeding motor in response to changes in boiler 5 pressure, and I have shown diagrammatically in Fig. 12 the wiring connections necessary for this purpose. I have also shown suitable connections to a timing switch operating in connection with the pressure switch for stopping and starting the fuel feeding motor at intervals when the pressure switch is open. In utilizing stoker grates of the rocking grate type, it is also essential that when the fuel feeding mechanism is stopped, the grates be left in level position, and this is accomplished by utilizing a limit switch which maintains the motor circuit closed after the pressure switch or the time switch has opened until the grates reach a level position. Such a structure is shown in 3O my prior Patent No. 1,897,579. My invention is directed to a device operating in conjunction with or independently of the control mechanism above referred to to connect and disconnect the drive shaft to the several feeding units. In order that the general operation of the con trol mechanism may be properly understood, I will ?rst describe the control circuits shown in Fig. 12. Referring now to Fig. 12, the letters A, B, and C indicate the current supply lines from a three phase source for operating the mechanism. These lines are brought in to a terminal board it and connected to the line terminals LI, L2, and L3. This board carries a relay H which is adapted when energized to close the contacts at i2, i3, and id for energizing the motor. When contact if is closed, line A is connected through 50 terminal Ll, contact if, winding of safety coil to the motor it. When contact i3 is closed, line B is connected through terminal L2 and con tacts 53 to motor it; and, when contact id is closed, line C is connected through terminal L3, 55 2 2,110,977 contacts l4, and winding of the safety coil H to the motor. Since contacts |2, l3, and M are all closed by energization of relay II, it is evident that when this relay is energized the motor will C11 position and breaks the circuit at limit switch 23 to deenergize relay | |. The controls just described are not in them selves the novelty of the present application, and The safety devices l5 and I1 normally connect the terminals at |8 and IS in the line which I will now describe the operation of the circuit which controls the actuation of the stoker grates after the motor l6 has been energized. As shown in Fig. 12, line A is connected through leads to the relay I!. terminal Ll, contacts l2 and winding of safety be started; and, if for any reason the relay is deenergized, the motor will be stopped. These safety devices l5 10 and I1 are merely overload relays which open their contacts when an excessive amount of cur rent is being drawn by the motor |6. The terminal L| is connected through the con tacts l8 to the relay II, and the other side of 15 the relay is connected through the contacts I!) to terminal Cl which is directly connected to terminal C2. The hand switch 20, which is a three-position switch is connected directly to terminal L3. It is evident that, if hand switch 20 is moved to connect with its upper contact, an energizing circuit for relay H is immediately closed from, line A through terminal Ll, con tacts l8, winding of relay ||, contacts l9, ter minals Cl and C2, upper contact of switch 20, terminal L3 to line C. This would, of course, close contacts l2, l3, and I4 and energize the motor so that the operator may, at any time he desires by moving the hand switch 20 to its upper position energize the motor |6. 30 Now if the hand switch 20 is moved to its lower contact, line C is connected through ter minal L3, hand switch 20 to contact C3. The contacts of pressure switch 2|. time switch 22 and limit switch 23 are connected in parallel across contacts C2 and C3. Lines 24 and 25 lead from C3 and C2 respectively to the ter minals of the pressure switch 2|. Lines 21 and 28 connect the opposite terminals of time switch 22 to terminals C3 and C2, respectively. The 40 time switch is also shown with the usual ener gizing coil 29 which is connected on one side by the line 30 to terminal LI and on the other side through the line 21, switch 2|], to terminal L3 when the switch 20 is in lower position so 45 as to maintain the clock mechanism of time switch 29 properly energized. The limit switch 23 is connnected to terminal C3 by line 3| and to terminal C| by line 32, Cl being directly connected to terminal C2. This 50 places the limit switch in parallel with the pres sure switch and the time switch across the ter minals C2 and C3. Now if the hand switch 20 is in lowermost po sition, this connects line C through terminal L3 55 and switch 20 to terminal C3. Line A is already connected to terminal C2 through terminal L|, device |5 to line 33. Line 33 leads to terminal 10 SI of the supervisory control device 34. Line 32 connects to terminal S3 on the panel of the con trol device 34, and this terminal in turn is con nected by line 35 to one side of each of the solenoids 36, 31, and 38. For the purpose of 15 clarity, I will describe the circuit controlling the solenoids 36, 31, and 38 with the assumption that the hand switch 20 is on its upper contact to energize the motor l6. This places line C in direct connection with terminal Cl and C2. 33 indicates a rotary cam switch which is directly connected by line 40 to terminal SI and line 33 which is in turn connected to line A when the motor is energized. The cam switch 39 has three contacts 4|, 42, and 43 which connect through 25 the hand switches 44, 45, and 46, respectively, to terminals S4, S5, and S6, which are in turn con nected by lines 41, 48, and 49 to the solenoids 36, 31, and 38, respectively. ‘Thus, if the contact 40’ of the cam switch 39 30 engages contact 4 I, then switch 44, which is nor mally closed, will direct current from line A through terminal LI, contact I2 of relay | I, wind ing of safety device I5, line 33, terminal SI, line 40, contacts 40', and 4|, switch 44, terminal S4, line 41 to solenoid 36; and then over a return cir cuit through line 35, terminal S3, line 32 to ter minal C I, then to terminal C2 and through switch 20 and terminal L3 to line C. Solenoid 36 will thus be energized. Over similar paths solenoid 31 will be energized when contact 40’ engages contact 42 and switch 45 is ‘closed, and solenoid 38 will be energized when contact 46’ engages contact 43 and switch 46 is closed. I have also shown push button switches 50, 5|, and 52 connected directly on one side to line 40 and on the other side to terminals S4, S5, and S6 so that by manually closing switch 50 for example when the motor I6 is running the sole noid 36 may be operated even though contact 40' is not in engagement with contact 4|. The circuit over which solenoid 36 is energized by closure of switch 50 leads from line A through terminal Ll, contacts |2 of relay ||, winding of 55 safety device l5, line 33, terminal SI, line 40, branch line 53, closed contact of switch 50 to contacts I8, relay ||, contacts I9, and terminal terminal S4, line 41, winding of solenoid 36, and Cl. back over lines 35 and 32 through terminals C|, 60 C2, and switch 20 to terminal L3 and line C. Now if the automatic control devices such as pressure switch 2| and time switch 22 are in cir cuit, there is really no difference in the opera tion of the devices 36, 31, and 38 as in this case, so long as either pressure switch 2|, time switch 65 22, or limit switch 23 happen to be closed and 20 is in its lower position, the energizing circuit for element 36 will extend from line A over the path Therefore, if either switch 2|, 22, or 23 is 60 closed, a circuit for energizing the relay II will be completed when the switch 20 is in its lower most position. It is evident, therefore, that the motor may be started by the closing of the pres sure switch 2| assuming that the hand switch 65 20 is in its lower position, and, if pressure switch 2| is maintained open, the periodical closing of switch 22 will also energize relay ||. The limit switch 23, as will be brought out later, is only open when the stoker grates are in level 70 position. The grates are, therefore, stopped in level position, and limit switch 23 cannot start the motor l6 from this position. However, if the motor is operating and both switches 2| and 22 are open, the limit switch 23 will maintain the 75 motor energized until it moves the grates to level previously described to line 33, then through the control 34 to terminal S4 and line 41 and back 70 over line 35 and 32 to terminal Cl and from ter minal CI to terminal C2. The circuit is com pleted from terminal C2 in case pressure switch 2| is closed over line 25, contacts of pressure switch 2|, line 24, terminal C3 to switch 2|] at its 75 3 2,110,977 lower. contact which connects up line C to com plete the energizing circuit for 36. Similarly, if the time switch 22 is closed, the energizing cir 'cuit for 36 will be closed through the lines 2'! and 28 and the closed contacts of time switch 22. When the limit switch 23 is closed and the other two switches are open, the energizing circuit for 36 may be traced over the following path: From line A, through terminal Ll, contacts l2 of relay I I, winding of safety device l5, line 33 to terminal 10 SI of control device 34, then through the control device 34 to terminal S4, line All to 36, back over line 35 to terminal S3, then through closed contact of limit switch 23 to terminal S2 and over line 3! to terminal C3 and then to switch 28 at its lower contact back to terminal L3 and line C. The manner in which the solenoid devices 35, 31, and 38 may be periodically energized by the cam switch device 39 at any time the motor is is running will, it is believed, be clear from the above description. Also, it is believed to be evident that any time the motor I6 is running, either of the devices 35, 31, or 38 may be ener gized by pressing the corresponding push but ton 50, 5!, or 52. I will now describe the mechanism which is caused to be operated by the energization of the elements 36, 31, and 38. I have shown my invention as applied to a fuel 3O feeding device utilizing stoker grates of the rock ing type. These grates are indicated by the numeral 53' (see Fig. 2) and there are three sec— tions or units such as 54, 55, and 56 all of which are operated from a common drive shaft 51 which in turn is driven from motor In by means of a disc and crank pin 58, link 59. and arm 60. Suit able bearings 51a, 51b, and 51.0 are provided for the shaft 51. In addition, a link 6! connects a second arm 6|’ ?xed on the shaft 51 to a similar arm 52 mounted on the shaft 63 which drives the cam switch 39. The connections between the shaft 5‘! and the three fuel feeding units 54, 55, and 56 are the same for each unit. These con nections are shown most clearly by Figures 1, 10, 45 and 11. The rocking grate bars are connected by depending arms such as 64 to the actuating link 65 which in turn is secured to the arm 65 which is pivotally mounted upon the shaft 51. A ‘suitable sleeve bearing 5‘! serves to take the wear 50 of the arm 66 off the shaft 51. This sleeve bear ing is secured to the member 68 which is in turn carried by the shaft 5‘! and secured thereto by suitable pin 69 so as to rock with the shaft. The member 66, it will be noted, is forked at ‘m 55 to provide two arms which ?t on opposite sides of the member 68. and a shear pin ‘H carries a roller 12 between the two arms. The member 68 has the shoulder 13 thereon which is adapted to engage the roller when the member 68 and shaft 60 5'! are rocked in a counterclockwise direction so as to force the roller 12 and with it the arm 65 to move with the shaft in this direction. Opposite the shoulder 13 the member 68 has pivoted there to .a pawl ‘M which in its normal inoperative posi tion swings down by its own weight into the posi tion shown in full lines in Fig. 11. The position shown in Fig. 11 is that of resting position for the fuel feeding grates, and it is believed to be evident that, if the shaft 51 and member 58 are rocked in a clockwise direction from this position, the roller 12 will ride between the mem ber 58 and the pawl ‘It. Now, if the pawl ‘M is raised up into the dotted line position shown in Fig. 11, the same rotation will cause the end of this pawl to engage the roller ‘i2 and thus move the arm $6 with the shaft 51 thus rocking the grates 53 to cause a fuel feeding operation. It should be understood, of course, that each of the fuel feeding units 54, 55, and 56 is connected to shaft El by mechanism like that shown in Figs. 10 and 11. The pawl W- has the heavy spring extension '55 projecting toward the furnace, and this extension is adapted to be engaged by the depending arm To depending from the solenoid device When 10 the solenoid device 35 is energized, it rocks the arm ‘if; from the full line position shown in Fig. 11 to the dotted line position shown in this ?gure. The extension '55 then, when the shaft 51 is re turning a counter-clockwise direction to the 15 position shown in Fig. 11, will be caught by the end of the arm ‘it to move the pawl "ail up into the dotted line position shown in Fig. 11, and thus cause the pawl to engage the roller ‘l2. It will be noted that the end face ‘if of pawl ‘is is so shaped that once it is pressed against the roller '52 and held there by the force necessary to turn the arm it cannot fall out until the pres sure is released or until the clockwise stroke of the shaft 51 is completed. The energizing of the 25 solenoid devices such as 35 is so timed with re spect to the rocking of shaft 5? that the arm. “i6 is swung into its dotted line position while the spring member '55 is out of the way. This timing operation will be brought out more clearly after 30 the mechanism has been fully described. Of course. if the arm '56 is caused by hand operation of push button switches such as as to to move toward the member it when the member ‘i5 is in the full line position shown in Fig. ll, nothing will happen until the shaft 5? has swung far enough to bring 75 below the end of the arm ‘is. From the above description, it is believed to be evident that when the solenoid device 3% is ener gized to swing arm "68 out into the path. of the 40 spring '55, the pawl will serve to connect the arm to the shaft Ell for rotation with the shaft in a clockwise direction; and naturally the rota tion in the opposite direction will. through the medium of the roller ‘l2 and the shoulder 18. bring 45 the arm 65 back to the position shown in Fig. 11 on the return stroke. The manner in which solenoid device the arm ‘ill will now be described. moves Referring to Figs. 8 and 9, the solenoid device 50 36 is housed in a casing '18 which is suitably mounted on a furnace as shown in Fig. and further to protect the solenoid device from the dust and dirt around a furnace, a cover or hous ing 19 hooks into the notch at 8%) (see Fig. 11) at 55 the top of the casing ‘l8 between the mounting lug of the casing and the furnace wall. This housing projects out over the device 68 mounted on the shaft 5? and thus keeps the falling ma terial such as particles of coal and the like from disturbing the operating mechanism. The lower end of the casing 3 has the recess 36 cast there in, and the arm l8 extends up into this recess where it is mounted upon shaft that projects through the walls of the recess 3 i, and is provided 65 These at andits35arms opposite to the arepin ends connected 85with which the bypasses the arms coil through 82' springs and the lower end of the solenoid plunger 5?. The coil 70 38 is energized over the wires 35 and M connected to the terminals such as 89 and 9d. The numeral Qt indicates the laminated frame of the solenoid, and the numeral 92 indicates an extension from. the upper end of the plunger 87 which carries a 75 4 2,1 10,977 stop piece 93 of non-magnetic material to engage the spring 94 when the solenoid plunger is raised upon energizing of the coil 88. The purpose of the spring 94 is, of course, to insure release of the plunger and its downward movement when the energizing circuit of the solenoid is broken as otherwise the residual magnetism of the lamina tions 9| and the plunger 81 might hold the plunger in raised position. It is believed to be 10 evident from an inspection of Figs. 8 and 9 that, when plunger 87 is raised, the arms 82’ and 83 will swing the arm ‘I6 into the dotted line posi tion illustrated in Figs. 9 and 11 for engagement with the spring ‘I5. 15 The manner in which the solenoid is energized has already been described in connection with Fig. 12. I will now describe the mechanism of the con trol device 34. Referring now to Figs. 3 to '7 inclusive, I have already described how the drive shaft 51 is con nected through arm SI’, link BI and crank arm 62 to the driving shaft 63 for the control de vice 34. The drive shaft 63 has a depending arm 25 95 (see Fig. 4) which engages an adjusting screw 96 on the frame 91 that carries the limit switch 23. The limit switch 23, as shown, is a mercury switch in which the two contacts such as 98 and 99 are normally separated when the arm 95 is in 30 the position shown in Fig. 4. This position of arm 95 corresponds to the raised position of the arm 02 which corresponds to the level grate position of arm 66 as shown by Figs. 1 and 11. In other words, the limit switch 23 is open when the grates are level. However, when the arm 95 is moved to the right from the position shown in Fig. 4 in response to a downward pull on arm 62, the weight of the frame 91 levels off the mercury switch 23 since the frame 91 can turn about its 40 pivot at I00. The shaft 63 has an arm IOI which is linked by means of link I02 to the arm I03 of the clutch device I04. Link I02 is slotted as indicated at I02’ so that, while there is a downward move 45 ment of arm I03 in response to down movement of arm IOI to the limiting position shown in Fig. 4, the upward movement of arm IOI does not move arm I03 upward—the pin on arm IOI mere ly riding in the slot of link I02. A spring I05 is 50 connected at its one end to the housing I06 of the control device 34 and is connected under tension at its other end to arm I03 so that it tends to draw arm I03 upwardly at all times. Clutch device I04 is mounted on shaft I0‘I, but 55 is free to rotate thereon. This clutch device has mounted thereon a pin I08 which engages with a cam I09 for adjusting the amount of rotation which will be transmitted to clutch device I04 for 60 each movement of shaft 63 and arm IOI. Within the ?ange III! of clutch device I04, there are mounted a series of arms such as III, H2, and H3 which are urged by means of the springs II4 outwardly against the ?ange IIO, these arms be 65 ing pivoted to a central member II5 that is se cured to shaft I01 by pin II6. It will be noted that the arms such as I II are slightly offset from radial position so that rotation of member I04 in a clockwise direction causes these clutch arms 70 to engage or press against the ?ange H0 and thus rotate the central member II5 with the clutch member I04. The shaping of the arms such as III, H2, and H3 in order to obtain the proper clutching ef 75 fect is one that involves considerable di?iculty, and I have discovered that by making these arms in a certain fashion I can obtain a very effective one-way clutch action. The outer face of the arm such as III is curved on the same radius as the inner ?ange IIO so that the entire face may engage the ?ange. One edge of this end face of the arm is shorter than the other and the length of the arm must be such as to permit the short edge to approach as closely as possible to the intersection of a radial line through the pivotal 10 axis of the rim I I0 and the pivotal axis of the arm with the rim. In the ?gure I show the short edge as not quite reaching such intersection as allowance must be made for inaccuracies. This permits the full end face of the arm to engage the 15 rim. If the arm is too short then it sticks and won’t release, if too long it won’t grip and slides on the rim. Since the bearing between the rim and end of the arm is quite large it is slow to wear and gives a long useful life. It appears 20 necessary however to follow dimensions closely. For example, with the ?ange IIO made on a ra dius of one and one-fourth inches and the pivot of the arm III spaced one-half inch outwardly from the center of the shaft I 01, the arm having 25 a one-fourth inch face to engage the ?ange IIO, the distance from the pivot center of the arm to the nearest end of the face of the arm that en gages the ?ange H0 should be approximately one-sixteenth of an inch shorter than the dis 30 tance from the pivot center to the other end of the face. With these proportions, I ?nd that the clutch operates very smoothly in transmitting the rotary motion of the member I04 to the member I I5 in one direction and releases easily to permit 35 reverse rotation of the member I84 without turn ing the member II5. It is believed to be evident from an inspection of Fig. 4 that, when arm 62 is pulled down by the link 6|, the spring I05 will be allowed to pull the 40 arm I03 upwardly and to turn the member I04 in a counterclockwise direction. The pin I08 limits the amount of this motion, however, by striking against the cam surface on the plate I09. Then on the reverse stroke when the arm 62 is 45 moved upwardly the arm IOI will move the disk I04 back down to limiting position, but the amount of movement of I04 will, of course, be only the amount which it was allowed to move in a counterclockwise direction by the pin I08 and 50 cam I09. In this clockwise rotation of I04, the clutch arms cause the member II5 to rotate with I04. By turning the cam plate I09, by means of the ?nger piece III, the amount of rotation of the member II5 for each rocking motion of the 55 shaft 63 can be varied over a wide range. In this way, angular movement of shaft I0‘! step by step in one direction is accomplished. On the top of the casing I00 there is an indicating plate IIO which may be suitably marked as indicated 60 in Fig. '7 for indicating the setting of the ?nger piece I I1. Referring now'more particularly to Fig. 3, it will be noted that there is a second clutch disk I20 opposite the member I54 which is engaged by 65 arms I2I. The arms IZI are exact duplicates of arms such as III, H2, and I I3 and make the same angle with the radius through their pivots from the shaft I0'I as arms III, IIZ, and H3 do. Disk I20 is stationary, being keyed in the housing I05 70 as indicated at I22. The clutch arms I2! and disk I20, therefore, act to prevent rotation of H5 in a counterclockwise direction although permitting it to rotate freely in response to the force trans 75 5 2,110,977 mitted upon clutch device I04 through the arms Ill, H2, and H3. The motion of the shaft I0? is transmitted through the bushing I23 of insulating material which is pinned to the shaft ml to a contact carrying disk i2il also of insulating material. This disk has the cut out notch at I25 (see Fig. 5) and the shoulder at I26 over which the con tact member i2? is bent. The contact member 10 527 is integral with the sleeve 52'!’ which is ?xed on the bushing i223. The disk i28, also of in— sulating material, is rotatably mounted on shaft till and carries a series of spring pressed contacts iES, ltd, and 535 which correspond to contacts iii, 42, and 43 shown in Fig. 12, the contact i2‘! corresponding to contact 49' of Fig. 12. Suitable terminals such as I32 and I33 are provided in conjunction with the contacts I29, H0, and EM for connection to the wire leads shown in Fig. 12 20 as leading from contacts 13!, 42 and #3. Disk 528 carries also an arm Hit in contact with the sleeve i2'i’ which is also provided with a suitable ter~ minal 50, 5|, and 52 are ordinary commercial push button switches which are adapted to close cir cuit through them when the push buttons such as I40 are pressed. The switches 44, ‘i5, and 45, only one of which is shown in Fig. 4 and which are hidden by the switches 50, iii, and 52 in Fig. 6, are also a'standard commercial switch which are adapted to open and close their contacts in response to movement of the levers such as I M. Switch M and switch 50 are connected in the manner shown in Fig. 12, and this is also true of switches 45 and 5|, and 4E and 52. The wiring is left off in the mechanical ?gures for the sake of clearness. The terminal strip M2 is- the one on which the contacts SI, S2, etc. are mounted. 15 In order to make the operation of this device more clearly understood, I will assume that the time switch 22 is closed and the motor I6 is operating in accordance with the description given of the circuit in connection with Fig. 12. 20 With the motor running, the crank 58, through the medium of the link 59 and arm 60, rocks for connection to the wire 48 of Fig. the shaft 5?; and also the rocking of shaft 5'! 12. Disk 523 has an arm I35 which is connected -25 by link i371 to the arm £38 which is pinned to the shaft 63 so as to rock therewith. The disk i251 is moved by the shaft 5 ii? step by step in a clock wise direction at a rate depending upon the set ting of the cam E69, and, as it moves, the various '30 contacts such as IE9, H36, and IS! drop down onto through the arm 6 I ' link GI and arm 62 transmits the contact I27 to make circuit through the cam switching device from line 49 through terminal i335, arm I311, contact tilt, and contact i29, I35, or léii to the terminal (ii, 42, or 43. The action of 35 disks E25 and E28 will be best understood from Figures 3 and 5. Disk 92% rocks to and fro as shaft 63 rocks, and shaft 63 rocks in time with the rocking of shaft 5?. Disk I24, however, is moved along by shaft It‘! step by step in the di 40 rection indicated by the arrow in Fig. 5. The timing relation between shaft 55'? and disk E28 will appear from Figs. 1, 4, and 5. When shaft 57 is moved clockwise, shaft $3 is moved counterclockwise in Figs. 1, 4, and 5, and disk I 28 45 is, therefore, also moved counterclockwise. The disk I 24 is moved clockwise step by step during the clockwise movement of disk 528. On the counterclockwise movement of !28, or while shaft 51 is moving clockwise as shown in Figs. 50 1 and 11 to move spring ‘i5 away from bar ‘iii, the contact disk I24 is stationary. It is during this movement that the contacts I29, etc. drop 482'. When this point is reached, link I02 is pulled down which causes arm M3 to rotate the drum H34 in a clockwise direction as shown in 40 Fig. 4. The clutch arms III, H2, and H3 then grip the ?ange IN} and cause the member II5 to rotate in a clockwise direction thus rotating shaft ID‘! in the same direction, and shaft I01 carries with it the disk I24 and contact I2? mounted 45 thereon. While this action is taking place, disk H8 is also being rocked in a clockwise direction by arm I36, link I3l, and arm I38 which is mounted on shaft 53. This action will be con disk I25 along with it for the full stroke of H23. 66. clockwise movement of disk i228, its contact such he next or return stroke causes the contact such as I29 to drop off shoulder I26 into notch I25 to thus prevent that contact from engaging i2? again on the return stroke. The maximum angular movement of disk E24 by drum I?fl for one step is somewhat less than 65 the angular rocking movement of disk E28, and the contact element I2? is made of substantial width in comparison with the distance disk 528 moves in order to insure contact on the advance 75 lill moves up, the spring m5 pulls arm 503 up wardly to rotate drum EM in a counterclockwise direction until the pin I08 strikes the cam sur face of cam plate I09. Further movement of the 30 arm lilll merely causes this pin to move up in the slot I92’ of link Hi2. Now when the rocking motion is reversed and arm idl is moved downwardly in response to a downward movement of arm 62 by link 61 and 35 arm St’, the ?rst part of the movement merely moves the pin on arm Hill to the bottom of slot as E29 engages shoulder I21" and moves cam 55. spring 715 is out of the way. During the next 70 Rocking of shaft 25 63 causes arm MI to move up and down. As arm tinued until one of the contacts, say I31, drops 50 down onto contact I21 during the counterclock wise rocking movement of. I28 at which time a circuit will be completed from wire 48 through contact 48' which corresponds to arm I34 to contact E21 and then to contact I3I which cor responds to contact 133 to thus supply the current from line A over lines 33 and 46 up to the switch down on I2? to energize the solenoids such as 36 thus swinging bar ‘I6 at a time when the 60 a rocking motion to shaft 63. movement of the contacts. For example, contact I 21 is about equal in width to the distance it would move for an an angular movement of 30 degrees of disk 12%. The maximum angular movement of disk I25 by drum N34 is about 30 degrees, and the angular movement of disk I28 is about 40 de grees. ' Assuming that switch d6 is closed, this connects line 49 in circuit so as to supply current to the 60 solenoid device 38. Solenoid device 38 then at tracts its armature or core 31 pulling it upward and causing the stop on 93 at the top thereof to strike spring 94 and at the same time the springs 34 and 85 are caused to rotate the shaft 82 to swing the connecting arm ‘I6 from the full line position shown in Figs. 9 and 11 to its dotted line position. This positions the arm ‘I6 to engage on top of the spring ‘l5 on the return stroke of shaft 5'5 so as to move the pawl ‘I4 up into dotted line position as shown in Fig. 11. Then as the shaft 5?! is rocked in a clockwise direction as shown in Fig. 11, the pawl '54 engages roller 12 to move the arm 66 with the shaft, thus pulling the link 65 to the left to rock the grates upwardly 75 6 2,110,977 and to feed the fuel forward on unit controlled by the solenoid device 38. When the shaft 51 starts back in the opposite direction, that is when arm 60 is being pulled up wardly, arm 62 is also being moved upwardly, but prior to this on the clockwise stroke of shaft 51, arm 62 was pulled down which turned shaft 63 in a counterclockwise direction sufficiently to break the contact between l3l and I2‘! by pulling 10 the tip of l3l oif into the cut-out portion I25 of disk I24. This released solenoid device 38 and allowed its arm 16 to fall back into vertical posi tion. The pawl 14, however, could not become disengaged owing to the shape of its end 11. Going back now to the return or grate leveling 15 stroke of the shaft 51, the upward movement of arm 80 and arm 62 by the motor causes the shoulder 13 on member 68 to engage roller 12 and the member 14 to drop down in idle position. 20 The return stroke of the shaft, therefore, through the medium of shoulder 13 and roller 12, pushes the arm 66 back into the position shown in Fig. 11 thus to level the grates. During this stroke, arms liil and I38 are pulled downward resulting 25 in further advancing the member H5 through the medium of arm I03, disk I04, and clutch arms lli, H2, and H3, and this by rotating shaft in’! steps the disk I24 one step farther around in a clockwise direction. The stepping action 30 would then continue until another contact such as I30 dropped onto contact [2‘! when the sole noid device 31 is energized to rock the grates con trolled by it in the same fashion just described. In this manner, the different fuel feeding units 35 are operated automatically in timed relation one after the other so long as the motor remains energized. If at any time while the motor is energized the operator feels that one of the feeding units should be given an extra operation, he merely presses the push button such as 50, 5|, or 52, mounted thereon, and this will energize a solenoid device 36, 3?, or 38 directly from line A over line 33, line 40, and line 53 through the contacts of the closed switch 50, 5|, or 52 and its associated line 41, 48, or 49. The actuation of the solenoid de vice will connect the shaft 51 to that particular feeding unit and operate it. The manual opera tion leaves the automatic operation undisturbed 50 as to timing, and the automatic operation then continues in the fashion hereinbefore described. From the above description, it is believed that the construction and operation of this device will be clear to those skilled in this art and the advan 55 tages thereof readily apparent. Having thus described one speci?c form of my drive member to said mechanism, control means for controlling the connecting means comprising an actuating member movable into position to cause the connecting means to connect the drive member to said mechanism, electro-magnetic means for operatively moving said actuating member, and a cam switch driven from said drive member for periodically energizing said electro-magnetic means. 3. In a control device for furnaces, a plural ple the drive member to the unit, and control means for said electro-magnetic devices com prising a cam switch driven from said drive mem electro-magnetic devices successively. 4. In a control device for furnaces, a plurality of rocking grate units and a common drive mem ber and individual connecting devices between each unit and said member normally maintain ing the units disconnected from the drive mem ber, electro-magnetic devices one for each unit each adapted when energized to cause the con necting device for that particular unit to cou ple the drive member to the unit, and control her and having contacts, and circuit connec tions connected with said contacts for successive electro~magnetic devices. 5. In a control device for furnaces, a plurality 40 of rocking grate units and a common drive mem ber and individual connecting devices between each unit and said member normally maintain ing the units disconnected from the drive mem ber, electro-magnetic devices one for each unit 45 each adapted when energized to cause the con necting device for that particular unit to cou ple the drive member to the unit, and control means for said electro-magnetic devices com prising a cam switch driven from said drive mem ber and having contacts, and circuit connections cause the connecting means to connect the drive member to said mechanism, electro-magnetic means for operatively moving said actuating member, a cam switch driven from said drive member for periodically energizing said electro 70 magnetic means, and manually operable means to energize said electro-magnetic means between the energizations thereof by said cam switch. 2. In a furnace operating system, a drive member, a rocking grate, a grate rocking mecha 75 nism, and connecting means for connecting the 50 connected with said contacts for successively en ergizing the electro-magnetic devices, said elec tro-magnetic devices each consisting of a sole noid, a pivoted arm, and resilient means con energized. nism, and connecting means for connecting the drive member to said mechanism, control means for controlling the connecting means comprising an actuating member movable into position to 35 ly energizing the electro-magnetic devices, and manually operable switches for energizing said secure by Letters Patent is: 60 member, a rocking grate, a grate rocking mecha 30 means for said electro-magnetic devices com prising a cam switch driven from said drive mem invention, what I claim as new and desire to ' 20 ber and having contacts, and circuit connections connected with said contacts for energizing the necting the solenoid and said arm for moving the arm into operating position when the solenoid is 1. In a furnace operating system, a drive 10 ity of rocking grate units and a common drive member and individual connecting devices be tween each unit and said member normally main taining the units disconnected from the drive member, electro-magnetic devices one for each 15 unit each adapted when energized to cause the connecting device for that particular unit to cou 55 6. In a control device for furnaces, a plurality of rocking grate units and a common drive mem 60 her and individual connecting devices between each unit and said member normally maintain ing the units disconnected from the drive mem ber, electro-magnetic devices one for each unit each adapted when energized to cause the con 65 necting device for that particular unit to cou ple the drive member to the unit, and control means for said electro-magnetic devices com prising a cam switch driven from said drive member and having contacts, and circuit con 70 nections connected with said contacts for suc cessively energizing the electro-magnetic devices, said control means having an adjusting device for varying the length of time between ener gizations of the electro-magnetic devices. 75 2,110,977 7 7. In a control device for furnaces, a plurality of. rocking grate units and a common drive mem said electro-magnetic devices comprising a cam switch driven from said drive member and hav~ ber and individual connecting devices between each unit and said member normally maintaining 01 the units disconnected from the drive member, electro-magnetic devices one for each unit each adapted when energized to cause the connecting device for that particular unit to couple the drive member to the unit, and control means for ing contacts, and circuit connections connected with said contacts for successively energizing the electro-magnetic devices, and manually operable switches in parallel with the cam switch contacts for energizing said electro-magnetic devices. GEORGE A. KOHOUT.